Time slows down sometimes. Seconds are minutes, and you experience “eternity in an hour”.
I’ve had it happen while riding my bike, playing tennis, playing computer games. The perception is that time has actually slowed. The difficult game becomes easy, the bike slides across the dirt, and you feel every grain gripping and releasing. Everything is automatic. It feels like an altered state of consciousness. In a good way. I’ve heard it called The Zone.
Drive at high speed on the freeway for a while and 20 mph feels slow enough to get out and walk. But go 20 mph for some time, and suddenly 60 feels like you’re flying. So it’s almost like we adjust our internal clock to mesh properly with our surroundings, to properly display our reality. But why can’t we move around in slow motion all the time? Why can’t we turn our perception clock up to 11, at will?
If we have our own personal time (observers don’t notice anything slowing down), and yet it feels like the world is slowing down, what’s going on? Are we slowing down our version of the universe, do we each have our own copy, which occasionally goes out of sync with everyone else’s, and we experience an unfortunately brief moment in the zone, then snap back in sync?
That would be cool. But most likely, it’s just focus, pure concentration on a single task giving us the illusion that we’re temporarily breaking free of time’s grasp.
So, our perception is altered, but observers notice nothing. Isn’t that what general relativity is about? A mystery for another day. My brain hurts.